WASHINGTON - The Forest Service has spent more than $2 billion battling forest fires around the country — a new record as wildfires blacken the American West in one of the nation’s worst fire seasons.

Wildfires have ravaged the West this summer with 64 large fires burning across 10 states as of Thursday, including 21 fires in Montana and 18 in Oregon. In all, 48,607 wildfires have burned nearly 13,000 square miles (33,586 square kilometers) in forests so choked with trees that they are at “powder keg levels,” as one Forest Service ecologist put it.

Agriculture Secretary Sonny Perdue said the severe fire season means officials “end up having to hoard all of the money that is intended for fire prevention, because we’re afraid we’re going to need it to actually fight fires.”

The emphasis on firefighting means that money for prescribed burns, insect control and other prevention efforts is diverted to putting out fires in what Perdue called a self-defeating cycle. The end result is that small trees and vegetation remain in the forest for future fires to feed on.

“That’s wrong, and that’s no way to manage the Forest Service,” Perdue said.